Description

Improper headspace may be dangerous to theshooter as well as an impairment to accuracy. The proper use of aHeadspace Gage is the most reliable way to test the length of a riflechamber. Forster Headspace Gages are made to exacting manufacturingstandards to ensure accurate testing of your rifle’s chamber.

Forsteroffers three lengths of headspace gages per rifle caliber. In orderfrom the shortest to longest, they are: GO, NO-GO and FIELD:

1. GO: Corresponds to the minimum chamber dimensions. If a rifle closes on aGO gage, the chamber will accept ammunition that is made to SAAMI’smaximum specifications. The GO gage is essential for checking anewly-reamed chamber in order to ensure a tight, accurate and safechamber that will accept SAAMI maximum ammo. Although the GO gage isnecessary for a gunsmith or armorer, it usually has fewer applicationsfor the collector or surplus firearms purchaser.
2. NO-GO: Corresponds to the maximum headspacerecommended for gunsmiths chambering new firearms. This is NOT aSAAMI-maximum measurement. If a rifle closes on a NO-GO gage, it maystill be within SAAMI specifications or it may have excessive headspace.To determine if there is excessive headspace, the chamber should thenbe checked with a FIELD gage. The NO-GO gage is essential for checking anewly-reamed chamber in order to ensure a tight and accurate chamber.
3. FIELD: Corresponds to the longest safeheadspace. If a rifle closes on a FIELD gage, its chamber is dangerouslyclose to, or longer than, SAAMI’s specified maximum chamber size. Ifchamber headspace is excessive, the gun should be taken out of serviceuntil it has been inspected and repaired by a competent gunsmith. FIELDgages are slightly shorter than the SAAMI maximum in order to give asmall safety margin.